Since their advent, airplanes have been susceptible to stalls which occur when an air foil, e.g. a wing, is unable to provide sufficient lift to permit the pilot of the aircraft to control the aircraft, e.g. maintaining level or climbing flight. Stalls can lead to catastrophic situations such as the aircraft crashing to the ground and loss of life.
Stalls can occur due to the disruption of laminar airflow over a surface of the airfoil which often occurs when an angle of attack of the aircraft is too steep. In such an event, the laminar airflow can become turbulent, diminishing the lift provided by the airfoil.
Aircraft component manufacturers have developed mechanical angle of attack vanes which are placed on aircraft fuselage. The mechanical angle of attack vanes provide a warning to the aircraft's pilot when the aircraft's angle of attack reaches a threshold indicative of possible, future occurrence of a stall condition. Other sensors, such as tubes and other vanes are used to detect the reversal of airflow over a surface of the airfoil which are also used to provide a warning to the pilot of a stall condition.
Such sensors are imperfect. The sensors are susceptible to severe weather conditions, such as icing, and mechanical wear which impair or incapacitate the sensors. The other sensors provide warnings that are untimely, providing the pilot with too little time to change the vector velocity of the aircraft to avoid a stall. Therefore, there is a need for a more robust way to provide stall warnings prior to the occurrence of such stalls.